The goals will be achieved by a) evaluating obesity, energy balance, and physcial activity in relation to cancer incidence and survival;b) Improving assessment of energy intake, output, and body phenotype;c) Evaluating biomarkers to determine mechanisms including inflammatory cytokines (CRP, IL-6, TNF-alpha), growth factors and their major binding proteins (IGF-1 and IGFBP-3), steroid hormones (testosterone, estrogen, SHBG) in relation to cancer and intermediate outs comes such as weight loss and weight gain d) evaluate novel such as metabolomics in assessing obesity, energy balance, and physical activity and body phenotype and in relation to cancer risk.